The present invention relates to a method for measuring a driving power by means of an induction motor, in which a driving power of a power drive apparatus such as, for example, an automobile is measured by making use of an induction motor.
Heretofore, as an apparatus for measuring a driving power and a speed of an automobile is known a chassis dynamometer as shown in FIG. 1. Upon measuring a driving power of an automobile by means of the chassis dynamometer, driving wheels 11a and 11b of the automobile are positioned across a pair of rollers 12a and 12b and across another pair of rollers 13a and 13b, respectively, as shown in FIG. 1, to cause an equivalent inertia mass 14 which is preliminarily loaded onto a shaft of the roller 12b to be rotated by the driving torque of the driving wheels, so that a voltage proportional to an r.p.m. of the rollers 12a, 12b, 13a an 13b is generated in a hydraulic dynamometer or eddy-current meter 15 by the rotational energy of the equivalent inertia mass 14. The voltage generated by the eddy-current meter 15 is applied across the terminals of a slide resistor in a torque bridge 16. On the other hand, a reaction torque generated in response to power absorption by a driving power absorber (not shown) is applied to a torque arm of the torque bridge 16, and by the action of said reaction torque the torque bridge 16 is moved up and down so that the voltage applied by the eddy-current meter 15 may be divided thereby. And after this value has been compared with the torque and the r.p.m., the shaft output is indicated by a meter 17 in PS units.
Though a driving power of an automobile has been measured in the above-described manner, said chassis dynamometer requires a considerable skill for the purpose that both the automobile speed and the torque should be simultaneously adjusted for achieving a stable operation at a particular measuring point. In addition, the use of a hydraulic dynamometer or eddy-current meter 15 involves difficulties that a measurement efficiency is low, associated equipments such as a driving power absorber and the like are necessitated, and the construction becomes complexed.